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Ultrasonic bath

Discussion in 'Electronic Repair' started by Yianni, Aug 13, 2008.

  1. Yianni

    Yianni Guest

    This URL claims that the design is patented, hence my question:
    You are right. Finaly I found a patent number: 01301930.9 . But I found
    nothing for this patent. May a chinese patent.

    Don't trust the specification on chinese machines -especialy the inexpensive
    ones-... The specifications says "power", I think it's the power
    consumption!! On the other hand, it won't be surprise to be 20W...

    I was thinking another aspect. At the first post, I said a 50% frequency
    increase, in my mind I have the possibility of 100% increase. Even if the
    "transducer" resonate to a frequency, it would resonate to the double
    frequency too. With "transducer" I mean the transducer alone or the
    combination of transducer/tank.

    I will try to find the schematic anyway!
     
  2. Yianni

    Yianni Guest

    How about these "buzzer" shaped transducers: The photos are small, I can't understand. The buzzer/transducer of the
    ultrasonic is: diametre 40mm (1.5"), thickness 4mm (0.15"). The "normal"
    transducers are about 1000g weight, the specific I suppose about 25g.
     
  3. Franc Zabkar

    Franc Zabkar Guest

    I found this URL for a "Model 2800: Miniature Ultrasonic Cleaner":
    http://www.asiabt.net/tradeleads/default2.asp?Category=8&SubCategory=235

    It makes the following certification claims:

    Approval & Patent? - ETL approval of USA(No.3012617) - CE approval of
    EU(No of LVD:H20211 S; No. of EMC:h20175) - GS approval of Germany(No
    EG0203104) - Our patent No is:01301930.9

    I tried searching for "Codyson" here ...

    http://etlwhidirectory.etlsemko.com/WebClients/ITS/DLP/products.nsf/$$Search?OpenForm

    .... and found two appliances, but no useful data. :-(

    This appears to be the PRC IPO database ...

    http://ensearch.sipo.gov.cn/sipoensearch/search/tabSearch.do?method=init

    .... but my searches produced nothing.
    How much power do you think a "buzzer" dissipates? ;-|

    If the transducer is not consuming most of the power, then what is? Do
    you think it is feasible for the appliance to consume 50W (or 20W) but
    only deliver a small fraction of that to the transducer?
    It makes no sense to say that a transducer can "resonate" at twice its
    resonant frequency (unless you are talking about overtones maybe ???).
    I'm guessing that the cleaner's circuit automatically oscillates at
    the transducer's resonant frequency, ie the external components aren't
    that critical. I suspect that if you were to replace the transducer
    with a higher frequency type, the new transducer would oscillate at
    its own resonant frequency, not 42kHz. You may need to optimise some
    components, though, to ensure that the transducer looks like a pure
    resistance. The frequency characteristics of the ferrite toroid would
    need to be considered as well.

    - Franc Zabkar
     
  4. Go to JDR microdevices. They sell that kind of shit.
    http://www.jdr.com/ or 1-800-538-5000
     
  5. I may need a single 22V10-10 or -15 programmed. I thought my PAL programmer
    was working but the burnt PAL behaves strangely in a way that suggests
    it may have internal incorrect logic. It also doesn't pass the programmer's
    test wiht respect to the test vectors (but I'm not sure that this ever
    really worked properly).

    I'll pay for the PAL or send a raw one and the .JED file to anyone who
    might volunteer. :)

    Or, if someone has a working programmer they'd like to sell.....

    Thanks!

    --
    sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
    Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
    +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
    | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

    Important: Anything sent to the email address in the message header above is
    ignored unless my full name AND either lasers or electronics is included in the
    subject line. Or, you can contact me via the Feedback Form in the FAQs.
     
  6. Franc Zabkar

    Franc Zabkar Guest

    I have a Sunshine Expro-60 that has that particular PLD in its device
    list. However, I'm in Australia.

    - Franc Zabkar
     
  7. Well, if you could email the programmed part... :)

    Actually, I think I found a problem in the logic so this may be a
    non-issue. Tow pins swapped. :( It was my lack of confidence in
    the programmed more than anything. It's an INLAB28, 20 years old, and
    I know there were always problems with CUPL and the programmer not
    using the same squence to do the test vectors. but being 20 years
    old, my memory is probably more fuzzy than that of the programmer!

    Thanks!

    --
    sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
    Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
    +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
    | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

    Important: Anything sent to the email address in the message header above is
    ignored unless my full name AND either lasers or electronics is included in the
    subject line. Or, you can contact me via the Feedback Form in the FAQs.
     
  8. Yianni

    Yianni Guest

    Hello Franc,

    I found the same url. In this the Karin Co. Ltd claims it produces this same
    model...
    I insist, don't rely to chinese specifications, claims, etc. China is a
    country without copyright law at all. China is "selected" to produce
    imitation procucts, that's why no copyright law. If you see specifications
    saying: 50W, 42kHz, CE approval, patent no., etc, no surprise if you get:
    10W, 25kHz, no CE, no patent at all... Inside China, there is no punishment
    for a company if it uses CE, ETL, GS approvals signs if it has no approvals.
    They can make Rolex, Lacoste, or any imitation with no fear.

    The other ultrasonic with the conventional buzzer (20mm diametre, less than
    1mm thick) claims 30W!!!
    Now, I understand the difference with a "real" ultrasonic with two "real"
    transducers I have had. Time comparison for the same cleaning results:
    a. Real ultrasonic 60W : 0.5 min
    b. the ultrasonic we talk (50W) : 9 min
    c. the other ultrasonic with the buzzer (30W) : > 25 min...

    Yes, I thouhgt the second overtone.

    I don't know to say if it's correct or not. I'm just thinking.
    1.. The transducer (ceramic ultrasonic transduder, like a bigger buzzer) it
    has a mass of say 25g. It is glued on the tank, say 100g. And the tank is
    filled with water 400-600g. I wonder for its resonance frequency.
    2.. Just a question because I don't know. Could someone take a conventional
    small buzzer and make a circuit to work on the buzzer's resonace frequency,
    relying on the buzzer's characteristics without RC or other similar parts on
    the oscilator? If yes, then it is a possibility to be the same in this
    machine.

    I will try to find the schematic, and I will send a message.
     
  9. Franc Zabkar

    Franc Zabkar Guest

    Look at it another way. Why would you need a 7 amp relay to supply
    power to a "buzzer"? Why would you need such a large heatsink and two
    high current (?) transistors?

    I suggest you buy something like this ...

    http://www.p3international.com/products/special/P4400/P4400-CE.html

    .... and measure the power consumption for yourself.
    I had another look at the following patent. It suggests that a simple
    change to your circuit may enable your transducer to resonate at the
    first overtone (see Fig 3 of the PDF file). It also confirms that the
    resonant frequency is dependent on the mass of water.

    OSCILLATOR CIRCUIT FOR AN ULTRASONIC CLEANER
    http://www.freepatentsonline.com/3584244.html

    The author states that "since the piezoelectric disc is closely
    coupled to the tank and the water load, the water depth in the tank
    effects the power transferred to the water and the resonant frequency
    of the transducer".

    "On all ultrasonic cleaning systems, some means must be employed to
    control the frequency at which the generator drives the transducer. If
    the generator is made to operate at a fixed frequency, poor
    performance will be encountered, since it is generally not possible to
    select one frequency which will always provide optimum operating
    conditions."

    "In the case of an ultrasonic generator, one is concerned with the
    behaviour of a piezoelectric transducer at the fundamental and perhaps
    the lower order overtone frequencies."

    This part looks very interesting:

    ====================================================================
    The preference the circuit shows in operating in the vicinity of some
    initially selected frequency is also desirable in suppressing
    tendencies to run at overtone frequencies. In some circumstances,
    however, this effect might not be great enough to completely prevent
    operation at the overtone. For instance, if the series resonant
    impedance of the fundamental frequency is slightly greater than at the
    first overtone, the circuit preference for lower impedance could take
    precedence and result in operation at the overtone were the shunt
    capacitor 86 not employed.

    Since the capacitor 86 is connected across the feedback transformer
    primary, its capacitive reactance lowers the impedance to overtone
    frequencies. This results in a lower primary voltage or, more
    directly, an increase in core saturation time. Thus, any tendencies to
    run an overtone are adequately suppressed, forcing the circuit to run
    at the fundamental.

    In the example given, it is desirable to operate at the fundamental
    frequency. Nevertheless, if operation at an overtone is desired, this
    may be accomplished by suitable selection of circuit elements and
    constants, and the principles of the invention may be employed to
    enhance operation at the preferred overtone.
    ====================================================================

    - Franc Zabkar
     
  10. mike

    mike Guest

    This thread sure has a lot of "fuss" over something that can be
    EASILY measured. Stick a signal generator and scope (or voltmeter) on it.
    That'll tell you what you can expect.
     
  11. Yianni

    Yianni Guest

    Hello Franc,

    These info are useful and they explain to me much about ultrasonics.
    Now, all explained!!! I can understand that transducer/tank/water can
    affect the resonant frequency. That's why the noise is different when the
    tank is full or half empty; some times it works much away from the resonate
    frequency because it makes louder noise (I feel it). It seems, it works in a
    steady frequency.

    I understand that needs the schematic someone to know how to increase the
    frequency. In the first I thought it would be easy someone to recognize the
    design. Seeing that the final transformer has only 3 pins, and the fact that
    the mains supply direct the transducer (as you said amplitude modulated) I
    understand the design should be more complicated. After all that, I closed
    the ultrasonic leaving it working the usual way!
     
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